抄録
As the method enabling to research simply the structure with the fine character at the initial design state, we proposed a new concept of CAE, First Order Analysis (FOA). Up to the present, we have developed the FOA tools based on beam elements with various cross-section properties, and applied to the stiffness analysis of the automotive structures. On the other hand, it is well known that the stiffness of the beam structure composed with thin shells declines as compared with simple beam theory because of elastic buckling of thin shells. On the basis of the effective width theory considering elastic buckling, the deflection analysis of the beam structure was carried out, and the result using the effective width theory was compared with that by non-linear finite element method. As a result, it was found to have sufficient accuracy as comparison with the result by linear finite element method.